/**
 * @author alteredq / http://alteredqualia.com/
 */

THREE.BloomPass = function ( strength, kernelSize, sigma, resolution ) {

  THREE.Pass.call( this );

  strength = ( strength !== undefined ) ? strength : 1;
  kernelSize = ( kernelSize !== undefined ) ? kernelSize : 25;
  sigma = ( sigma !== undefined ) ? sigma : 4.0;
  resolution = ( resolution !== undefined ) ? resolution : 256;

  // render targets

  var pars = { minFilter: THREE.LinearFilter, magFilter: THREE.LinearFilter, format: THREE.RGBAFormat };

  this.renderTargetX = new THREE.WebGLRenderTarget( resolution, resolution, pars );
  this.renderTargetX.texture.name = "BloomPass.x";
  this.renderTargetY = new THREE.WebGLRenderTarget( resolution, resolution, pars );
  this.renderTargetY.texture.name = "BloomPass.y";

  // copy material

  if ( THREE.CopyShader === undefined )
    console.error( "THREE.BloomPass relies on THREE.CopyShader" );

  var copyShader = THREE.CopyShader;

  this.copyUniforms = THREE.UniformsUtils.clone( copyShader.uniforms );

  this.copyUniforms[ "opacity" ].value = strength;

  this.materialCopy = new THREE.ShaderMaterial( {

    uniforms: this.copyUniforms,
    vertexShader: copyShader.vertexShader,
    fragmentShader: copyShader.fragmentShader,
    blending: THREE.AdditiveBlending,
    transparent: true

  } );

  // convolution material

  if ( THREE.ConvolutionShader === undefined )
    console.error( "THREE.BloomPass relies on THREE.ConvolutionShader" );

  var convolutionShader = THREE.ConvolutionShader;

  this.convolutionUniforms = THREE.UniformsUtils.clone( convolutionShader.uniforms );

  this.convolutionUniforms[ "uImageIncrement" ].value = THREE.BloomPass.blurX;
  this.convolutionUniforms[ "cKernel" ].value = THREE.ConvolutionShader.buildKernel( sigma );

  this.materialConvolution = new THREE.ShaderMaterial( {

    uniforms: this.convolutionUniforms,
    vertexShader:  convolutionShader.vertexShader,
    fragmentShader: convolutionShader.fragmentShader,
    defines: {
      "KERNEL_SIZE_FLOAT": kernelSize.toFixed( 1 ),
      "KERNEL_SIZE_INT": kernelSize.toFixed( 0 )
    }

  } );

  this.needsSwap = false;

  this.camera = new THREE.OrthographicCamera( - 1, 1, 1, - 1, 0, 1 );
  this.scene  = new THREE.Scene();

  this.quad = new THREE.Mesh( new THREE.PlaneBufferGeometry( 2, 2 ), null );
  this.quad.frustumCulled = false; // Avoid getting clipped
  this.scene.add( this.quad );

};

THREE.BloomPass.prototype = Object.assign( Object.create( THREE.Pass.prototype ), {

  constructor: THREE.BloomPass,

  render: function ( renderer, writeBuffer, readBuffer, delta, maskActive ) {

    if ( maskActive ) renderer.context.disable( renderer.context.STENCIL_TEST );

    // Render quad with blured scene into texture (convolution pass 1)

    this.quad.material = this.materialConvolution;

    this.convolutionUniforms[ "tDiffuse" ].value = readBuffer.texture;
    this.convolutionUniforms[ "uImageIncrement" ].value = THREE.BloomPass.blurX;

    renderer.render( this.scene, this.camera, this.renderTargetX, true );


    // Render quad with blured scene into texture (convolution pass 2)

    this.convolutionUniforms[ "tDiffuse" ].value = this.renderTargetX.texture;
    this.convolutionUniforms[ "uImageIncrement" ].value = THREE.BloomPass.blurY;

    renderer.render( this.scene, this.camera, this.renderTargetY, true );

    // Render original scene with superimposed blur to texture

    this.quad.material = this.materialCopy;

    this.copyUniforms[ "tDiffuse" ].value = this.renderTargetY.texture;

    if ( maskActive ) renderer.context.enable( renderer.context.STENCIL_TEST );

    renderer.render( this.scene, this.camera, readBuffer, this.clear );

  }

} );

THREE.BloomPass.blurX = new THREE.Vector2( 0.001953125, 0.0 );
THREE.BloomPass.blurY = new THREE.Vector2( 0.0, 0.001953125 );